1. Technical Field
The present invention relates to compositions comprising lipids and beneficial lipid soluble non-glyceride compounds and methods to produce such compositions. More specifically, the present invention relates to compositions for use in cosmetic, personal care and skin care applications and methods to produce such compositions.
2. Background Art
The cosmetic, personal care, and skin care industry uses a myriad of plant, vegetable, fruit, and seed oils in formulations such as treatment creams, massage and bath products, skin cleansing, and hair conditioning products.
These oils contain lipids; such as waxes, fatty acids, sterols and lipid soluble components; such as tocopherols and carotenoids, and have a variety of properties and functionalities.
Coverage of the upper layer of the skin with natural oils reduces trans-epidermal water loss (TEWL) and maintains water in the upper layer of the skin contributing to enhanced hydration. TEWL is a measure of barrier integrity and is defined as the quantification of water that passes from inside the body through the skin to the surrounding atmosphere via diffusion and evaporation. The stronger the barrier, the lower the TEWL.
The fatty acids can be non-essential fatty acids; such as oleic, palmitic, palmitoleic, lauric, and stearic acids or essential fatty acids; such as linoleic and linolenic. Fatty acids can be saturated (stearic, caprilic, palmitic) or unsaturated (oleic, linoleic) and can exist in their free form or as glycerol esters. They can be used in their anhydrous state or as an oil/water emulsion. Fatty acids are used primarily as a skin conditioner and as a carrier for other components.
Fatty acids are an important component of the skin's intracellular lipid lamellae matrix and human sebum. Human sebum includes more than 40% fatty acids; therefore, selected acids, when applied, can partition into the sebum and the follicular opening. Fatty acids are also part of the outer layer of the skin, the stratum corneum. The skin's barrier properties are partially dependent upon the unique organization of ceramides, sterols (mostly cholesterol), and free fatty acids arranged as extra-cellular lamellar bilayers between corneocytes.
Individual fatty acids have particular functionality with respect to cosmetic and skin care applications. For example, oleic acid has been shown to enhance skin permeation of various active compounds. It is theorized that the mechanism of action attributed for permeation enhancement is fluidization of the organized lamellar organization in the stratum corneum. Linoleic acid is known to play a role in maintaining an intact stratum corneum layer and to elevate the rate of epidermal cell proliferation and therefore skin renewal. Skin disorders such as eczema, psoriasis and dermatitis have been related to deficiencies in linoleic acid. Palmitoleic acid was found to exhibit anti-microbial activity effective against gram positive bacteria, suggesting usefulness in topical formulations for treatment of secondary gram positive bacterial infections.
Fatty acids are also used as a carrier for other lipids and lipid soluble compounds such as phytosterols, tocopherols, tocotrienes, and carotenoids. These compounds absorb more efficiently when combined with specific fatty acids. However, topically applied esterified fatty acids such as triacylglycerols must first be cleaved to their free acid form by lipase enzymes present in eccrine/sebaceous secretions. Topically applied free fatty acids can be absorbed directly. The kinetics of absorption of topically applied lipids and lipid soluble compounds increase with increasing ratios of free fatty acids to acyl glycerides.
Phytosterols are a naturally occurring plant sterol. It is well known that phytosterols have anti-inflammatory properties and are used in personal care products including anti-aging products. The breakdown and loss of collagen is a contributing factor to the aging of skin. Unprotected exposure to the sun accelerates this aging phenomenon. According to a study by Germany's National Institute of Health, topical treatments containing phytosterols are effective in blocking the reduced collagen synthesis after UV irradiation and have stimulatory effects. The study concluded phytosterols “may be useful additions to anti-aging products”.
Tocopherols and tocotrienes are valuable in skin care applications for their anti-oxidant properties that protect against DNA damage caused by environmental free radicals that promote premature aging. α-Tocopherol is an antioxidant responsible for quenching lipid peroxyl free radicals thereby protecting against acute and chronic UV-induced damage. Collagen synthesis and inhibition of collagen degradation was enhanced with tocopherol application thereby preventing wrinkle formation and preserving skin elasticity. In addition, tocopherols exhibit anti-inflammatory activity by decreasing prostaglandin signaling.
Carotenoids are also incorporated into skin care products to counteract premature aging caused by free radicals. Carotenoids are naturally occurring plant pigments that protect plants against excessive exposure to UV radiation and have been shown to provide photoprotection to light exposed human tissue. The human skin, as the boundary organ between the human body and the environment, is under the constant influence of free radicals (FR), both from the outside in and from the inside out. Carotenoids are known to be powerful antioxidant substances playing an essential role in the reactions of neutralization of FR (mainly reactive oxygen species ROS). Carotenoid molecules present in the tissue are capable of neutralizing FR, especially ROS, and are then destroyed. In a study published in Skin Pharmacol Physiol, it was shown that this UV protection is imparted with either oral ingestion or topical application and an accretive effect was demonstrated with combined oral ingestion and topical application.
In addition to their role in promoting skin health, carotenoids also have applications in beauty products. These plant pigments accumulate in the stratum corneum causing a yellow/red coloring of the skin, giving a healthier and more attractive appearance. As with the use of carotenoids for UV protection, the benefit of using carotenoids for skin coloration occurs whether the carotenoids are administered through oral ingestion or topical application.
The cosmetic, personal care and skin care industry desires natural and naturally derived products. Therefore there is a need for a composition derived from a naturally occurring lipid containing concentrations of compounds with desirable functionalities and a method to produce such compositions.
The cosmetic industry places a high value on these compositions. However, by-products and co-products are also created and uses for these products must also be found to contribute to the economic feasibility of the processes described herein. The expanded use of the products of the present invention add to the process economy of scale.
Rudolph Diesel developed the diesel engine in the 1890's. Because of its high power, efficiency and reliability, the diesel engine became the engine of choice for demanding applications. Rudolph Diesel envisioned the use of lipids as the fuel for this engine. However, the widespread discovery of petroleum oil made petroleum based diesel fuel cheap and abundant and it quickly became the fuel of choice for diesel engines.
Recent concern over the diminution of petroleum reserves and the environmental effects of diesel fuel has led to the search for alternative fuels for diesel engines. The products of the present invention are highly desirable as alternative energy feedstocks.
Environmental concerns are also driving the search for alternatives for other oleo chemical products, such as bio lubricants, foams, plastics, dielectric fluids, solvents, paints and coatings.
There is also a desire to produce animal feed products. Laying hens are fed lutein to give egg yolks a more desirable color. Isolated palmitic acid added to the finishing diet of beef cattle is known to improve marbling. The hog industry desires specific saturated/unsaturated fats ratios to promote leaner pork products.
Isolation and recovery of beneficial lipid-soluble non-glyceride compounds from various bio-based feedstocks has been practiced for many years. Fernandes and Cabral [Bioresource Technology 98 (2007) 2335-2350] reviewed recovery methods for phytosterols, with the most common methods involving recovery from distillates obtained during the deodorization of crude vegetable oils. Deodorizer distillates, especially of soy, corn, wheat germ and tall oil are enriched in phytosterols and hence are preferred feedstocks for recovering purified concentrates of these beneficial compounds. The methods addressed by Fernandes and Cabral are focused on obtaining phytosterol concentrates in excess of 50 wt % and more typically greater than 80 wt %. Many of the common recovery methods involve hydrolysis and saponification of esters followed by distillation of the unsaponifiable compounds, including phytosterols.
Rodrigues, et al. [Recent Patents on Engineering 1 (2007) 95-102] reviewed published methods for deacidification of vegetable oils, i.e. removal of free fatty acids (FFAs). Traditional deacidification approaches include chemical, physical and solvent extraction methods. Newer approaches include biological removal of FFAs by microorganisms and enzymatic esterification, supercritical fluid extraction and membrane processing. Rodrigues, et al. highlighted solvent extraction with short chain alcohols, alcohol/water mixtures and other polar solvents as particularly useful for deacidification of crude vegetable based oils; however, the focus is on removal of FFAs with retention of tocopherols and tocotrienols in the raffinate oil rather than isolation and recovery of these beneficial non-glyceride compounds in the solvent extract. In several cited examples, Rodrigues et al. show that addition of water (up to 20% w/w) to an alcohol helps to reduce the amount of neutral oil (triglycerides) lost to the solvent, yet the solvent retains FFA removal power. A further consequence of increasing water concentration in an alcohol/water solvent mixture is that beneficial non-glyceride compounds such as tocopherols, sterol ester and carotenoids partition to the raffinate phase. Thus water concentration in an alcohol solvent can be used to tailor the partitioning of glycerides and non-glycerides in the extract and raffinate phases. Solvent extraction has been applied to many plant based oils including canola, coconut, corn, cottonseed, olive, palm, rape, rice bran, sesame seed and various nut oils.
The tremendous growth of the United States ethanol industry over the past ten years has also resulted in the growth of ethanol byproducts including distillers dry grain with solubles (DDGS) and distillers oil (DO). Ethanol, DDGS and DO yields are currently about 21, 17.7, and 0.5 pounds per bushel of corn respectively (1 bushel=56 pounds shelled corn at 15.5 wt % moisture). Technology improvements are expected to increase DO yields to over 1 pound per bushel. Most US dry grind ethanol plants have installed DO recovery systems and hence a supply of almost 4 billion pounds of DO is theoretically available in the nearly 13.3 billion gallon US ethanol market.
Although corn is the predominant grain used for producing ethanol in the United States, milo, barley, wheat and other grains are also used. In the case of these other feedstocks, analogous distillers oil can also be recovered. Distillers oil produced primarily from corn fermentation is known as distillers corn oil (DCO) but can contain oils of other grains if fermented in the same facility. The term DO as applied herein refers generically to any oil recovered from a grain fermentation process, including corn.
In the conventional dry grind ethanol process, grain is ground, slurried in water, cooked and treated with enzymes to convert starch to sugars. Yeast then convert the sugars to ethanol and carbon dioxide during fermentation resulting in an ethanol rich “beer”. Ethanol is removed from the beer by distillation resulting in “whole stillage,” an aqueous slurry of unfermented dissolved and suspended corn solids. Whole stillage is separated with a decanting centrifuge into distillers wet grains containing the bulk of the suspended solids of whole stillage and thin stillage containing dissolved solids, fine suspended solids, protein and oil. Up to one half of the thin stillage is recycled to the cook step and the balance is concentrated to “syrup” in multi-effect evaporators. Distillers oil is typically obtained by centrifugation of partially concentrated thin stillage but can be recovered at various parts of the process. Syrup may be sold as is or mixed with distillers wet grains and dried to produce DDGS.
Investigators have shown that DCO has a composition distinctly different from crude germ oil or refined germ oil, i.e. edible corn oil for human consumption (Moreau et al., J. Am. Oil Chem. Soc. 2010, 87, 895-902; Winkler-Moser, Industrial Crops and Products 2011, 33, 572-578). Moreau et al. showed that free fatty acids in post fermentation corn oil (DCO) are 11-16% w/w, much higher than crude ethanol extracted whole kernel oil having about 1% w/w FFA or commercial edible oil (corn germ oil, refined, bleached and deodorized) having no measurable FFA. With respect to beneficial non-glyceride compounds, the levels of free phytosterols and hydroxycinnamate sterylesters in DCO were higher than those of corn germ oil and were comparable to those of ethanol-extracted corn kernel oil. The levels of tocopherols were lower in DCO than in either corn germ oil or ethanol extracted corn kernel oil. The levels of lutein and zeaxanthin in DCO were much higher than those in corn germ oil and were comparable to those in ethanol-extracted corn kernel oil. Thus DCO and other distillers oils offer valuable depots of FFAs and beneficial non-glyceride compounds if a cost-effective recovery process can be developed. The present invention provides for compositions and cost effective methods of obtaining valuable lipid compositions from distillers oil and other natural lipid sources.
Distillers oil is primarily sold as an animal feed component or as a feedstock for the production of fatty acid methyl esters (biodiesel). As a biodiesel feedstock, distillers oil commands a lower price than soybean oil due to distillers oil's relatively high free fatty acid content (>10 wt %). Modern ethanol plants continually strive to maximize the financial return on each bushel of purchased grain. A high value oil composition produced from distillers oil and enriched in beneficial lipid soluble non-glyceride compounds offers the ethanol producer a further opportunity to improve their financial return on grain.
U.S. Pat. No. 8,702,819 assigned to Poet Research Inc. discloses a corn oil composition containing less than 5 wt % free fatty acids and greater than threshold levels of specific carotenoids, e.g. greater than 50 micrograms/g lutein. Poet further discloses a method of obtaining the low FFA oil composition by treating DCO with alkali. Alkali neutralizes (saponifies) the free fatty acids making them much less oil soluble and de-emulsifies the oil for improved oil/water phase separation. The Poet patent emphasizes production of low FFA oil; however, the recovery of an oil composition enriched in beneficial lipid soluble non-glyceride compounds is not disclosed.
Therefore there is a need for efficient methods to produce compositions derived from low cost naturally occurring lipids containing concentrations of compounds with desirable functionalities.